Move meta and random to "aux" modules.

Wren now has three classes of modules:

- The one magic "core" module that's built in and always needed.
- Auxiliary libraries like "meta" and "random". These do not have any
  dependencies, so can be used even when you embed Wren inside an
  application. But they're also optional and can be disabled if you
  don't need them.
- CLI modules. These ones need libuv and are tied to the CLI wrapper
  around the VM.

util/wren.mk

@@ -19,6 +19,9 @@
 # Then, for the libraries, the correct extension is added.
 
 # Files.
+AUX_HEADERS := $(wildcard src/aux/*.h) $(wildcard src/aux/*.wren.inc)
+AUX_SOURCES := $(wildcard src/aux/*.c)
+
 CLI_HEADERS  := $(wildcard src/cli/*.h)
 CLI_SOURCES  := $(wildcard src/cli/*.c)
 
@@ -106,6 +109,7 @@ endif
 
 CFLAGS := $(C_OPTIONS) $(C_WARNINGS)
 
+AUX_OBJECTS    := $(addprefix $(BUILD_DIR)/aux/, $(notdir $(AUX_SOURCES:.c=.o)))
 CLI_OBJECTS    := $(addprefix $(BUILD_DIR)/cli/, $(notdir $(CLI_SOURCES:.c=.o)))
 MODULE_OBJECTS := $(addprefix $(BUILD_DIR)/module/, $(notdir $(MODULE_SOURCES:.c=.o)))
 VM_OBJECTS     := $(addprefix $(BUILD_DIR)/vm/, $(notdir $(VM_SOURCES:.c=.o)))
@@ -134,26 +138,27 @@ cli: bin/$(WREN)
 test: $(BUILD_DIR)/test/$(WREN)
 
 # Command-line interpreter.
-bin/$(WREN): $(CLI_OBJECTS) $(MODULE_OBJECTS) $(VM_OBJECTS) $(LIBUV)
+bin/$(WREN): $(AUX_OBJECTS) $(CLI_OBJECTS) $(MODULE_OBJECTS) $(VM_OBJECTS) \
+		$(LIBUV)
 	@ printf "%10s %-30s %s\n" $(CC) $@ "$(C_OPTIONS)"
 	@ mkdir -p bin
 	@ $(CC) $(CFLAGS) $^ -o $@ -lm $(LIBUV_LIBS)
 
 # Static library.
-lib/lib$(WREN).a: $(VM_OBJECTS)
+lib/lib$(WREN).a: $(AUX_OBJECTS) $(VM_OBJECTS)
 	@ printf "%10s %-30s %s\n" $(AR) $@ "rcu"
 	@ mkdir -p lib
 	@ $(AR) rcu $@ $^
 
 # Shared library.
-lib/lib$(WREN).$(SHARED_EXT): $(VM_OBJECTS)
+lib/lib$(WREN).$(SHARED_EXT): $(AUX_OBJECTS) $(VM_OBJECTS)
 	@ printf "%10s %-30s %s\n" $(CC) $@ "$(C_OPTIONS) $(SHARED_LIB_FLAGS)"
 	@ mkdir -p lib
 	@ $(CC) $(CFLAGS) -shared $(SHARED_LIB_FLAGS) -o $@ $^
 
 # Test executable.
-$(BUILD_DIR)/test/$(WREN): $(TEST_OBJECTS) $(MODULE_OBJECTS) $(VM_OBJECTS) \
-		$(BUILD_DIR)/cli/modules.o $(BUILD_DIR)/cli/vm.o $(LIBUV)
+$(BUILD_DIR)/test/$(WREN): $(AUX_OBJECTS) $(MODULE_OBJECTS) $(TEST_OBJECTS) \
+		$(VM_OBJECTS) $(BUILD_DIR)/cli/modules.o $(BUILD_DIR)/cli/vm.o $(LIBUV)
 	@ printf "%10s %-30s %s\n" $(CC) $@ "$(C_OPTIONS)"
 	@ mkdir -p $(BUILD_DIR)/test
 	@ $(CC) $(CFLAGS) $^ -o $@ -lm $(LIBUV_LIBS)
@@ -172,14 +177,21 @@ $(BUILD_DIR)/module/%.o: src/module/%.c $(CLI_HEADERS) $(MODULE_HEADERS) \
 	@ mkdir -p $(BUILD_DIR)/module
 	@ $(CC) -c $(CFLAGS) $(CLI_FLAGS) -o $@ $(FILE_FLAG) $<
 
+# Aux object files.
+$(BUILD_DIR)/aux/%.o: src/aux/%.c $(VM_HEADERS) $(AUX_HEADERS)
+	@ printf "%10s %-30s %s\n" $(CC) $< "$(C_OPTIONS)"
+	@ mkdir -p $(BUILD_DIR)/aux
+	@ $(CC) -c $(CFLAGS) -Isrc/include -Isrc/vm -o $@ $(FILE_FLAG) $<
+
 # VM object files.
 $(BUILD_DIR)/vm/%.o: src/vm/%.c $(VM_HEADERS)
 	@ printf "%10s %-30s %s\n" $(CC) $< "$(C_OPTIONS)"
 	@ mkdir -p $(BUILD_DIR)/vm
-	@ $(CC) -c $(CFLAGS) -Isrc/include -o $@ $(FILE_FLAG) $<
+	@ $(CC) -c $(CFLAGS) -Isrc/include -Isrc/aux -Isrc/vm -o $@ $(FILE_FLAG) $<
 
 # Test object files.
-$(BUILD_DIR)/test/%.o: test/api/%.c $(MODULE_HEADERS) $(VM_HEADERS) $(TEST_HEADERS) $(LIBUV)
+$(BUILD_DIR)/test/%.o: test/api/%.c $(AUX_HEADERS) $(MODULE_HEADERS) \
+		 $(VM_HEADERS) $(TEST_HEADERS) $(LIBUV)
 	@ printf "%10s %-30s %s\n" $(CC) $< "$(C_OPTIONS)"
 	@ mkdir -p $(dir $@)
 	@ $(CC) -c $(CFLAGS) $(CLI_FLAGS) -o $@ $(FILE_FLAG) $<
@@ -193,6 +205,9 @@ $(LIBUV): $(LIBUV_DIR)/build/gyp/gyp util/libuv.py
 	@ ./util/libuv.py build $(LIBUV_ARCH)
 
 # Wren modules that get compiled into the binary as C strings.
+src/aux/wren_aux_%.wren.inc: src/aux/wren_aux_%.wren util/wren_to_c_string.py
+	@ ./util/wren_to_c_string.py $@ $<
+
 src/vm/wren_%.wren.inc: builtin/%.wren util/wren_to_c_string.py
 	@ ./util/wren_to_c_string.py $@ $<